Hi milank,
The prices of closed-end funds vary based on two factors: the underlying value of the fund's holdings (be they stocks, other funds, bonds, or commodities), and an additional "discount" or "premium" to this underlying value. Both elements vary a great deal.
With the recent extreme volatility, the so called "transparency" of a security's underlying assets has been valued more than usual. Partly because closed-end funds are often less transparent than their contents, many of them have been trading at an unusually steep discount to their underlying value. This can make them especially interesting bargains if you are a buyer, but especially frustrating holdings if you purchased them when they were more richly valued.
We at FiLife cannot speak to the likelihood that any particular security will retain its current dividend. We are not experts in these securities, and cannot give "financial advice" per se. Generally speaking, to the extent that many different issuers are having to cut dividends, it would not be unusual if these funds had to do so also. (It would also stand to reason that once economic conditions are more favorable, dividends might be raised again).
As for whether you should sell now and buy CDs, that depends a great deal on your current financial situation: your risk tolerance, the time frame in which you need the funds, the rest of your portfolio, etc. You would do well to consult a "fee only" financial planner to help advise you about this.
One question to honestly ask yourself is, why did I buy/do I own these funds in the first place? Has anything fundamental about you or your financial situation changed? If they made sense for you to purchase at higher values, then it may not make sense to sell them when are "on sale".
Generally speaking, I would not advise anyone to sell their stocks at this point unless they never should have been in stocks in the first place. But again, a qualified professional should be able to evaluate all your circumstances and give you specific advice that best fits those.
I hope this helps!